have been answered. my colleague has this report. >> runners were struggling to the finish line, their families watching, at cheering. then the unthinkable. cheers became screams. a moment of celebration and triumphed shattered. on the streets of boston, sights and sounds more familiar in countries at war. pavement spattered in blood as two bomb blasts claimed their victims. it was the cruelest of moments. >> i saw a trash can explode.

people started throwing down the barricade and running over each other. i ran in the other direction as fast as i could. >> there was an explosion, the smoke. it was horrible. it was traumatizing. i do not know how else to explain it. >> i saw quite a few casualties. i saw one guy with his legs gone at the knees, ankles and feet missing, shrapnel wounds to the head. were least 140 people injured. three people are dead. it was a day the local hospitals had not seen the light of. .> multiple metallic fragments we removed palace and nails. >> this is martin richard.

his simple sign reads -- ,> no more hurting people peace. he was killed yesterday. his mother was seriously injured. in other victim had come to cheer on a friend. yesterday, this area was packed with runners and spectators enjoying the boston marathon. today, the center of boston is in lockdown. it has become a major crime scene. the question above all, why did this happen and who is responsible? a massive police hunt is now under way. new york and washington have tightened security and the fbi is in charge of what it calls a potential terrorist activity. this woman was doing a project on the marathon. she was standing at the finish

line filming. this is her footage. see that, all you want to do is help, but you do not know how. it is a terrible thing to witness. >> this morning in boston, there was a collective sense that somehow not just the city, but america, was attacked. >> i am grateful i am ok. on my run this morning, people were waving and smiling. i'm just grateful that everyone i know is ok. inamericans are united sympathy and grief as questions mount about the attack of the boston marathon. >> as president obama said today, there is still much to investigate. let's take a look now at the latest pictures we have of the forensic evidence being

recovered from the scene of the explosion there at the finish line of the boston marathon, just a few minutes away from where i'm standing and talking to you. you can see officer's going through debris, looking for a crucial clue. they are going to take everything they can to quantico, va., and try to reassemble the devices that were used. we understand that they were pressure cooker devices that may have been carried in black nylon backpack. we have considered the scale of the task ahead of the american officials trying to figure out who is behind us. bombing will reverberate in washington. not only in the flags at half mast and the need for tightened security, but as a challenge to a president visibly frustrated

by how little is known. >> we do not know if this was done by an individual or individuals. we do not have a sense of motive. >> he did call this an act of terrorism, a label he initially avoided. >> this was a heinous and cowardly act. given what we now know about what took place, the fbi is anvestigating this as act of terrorism. >> america has lived with terrorism for a while. the attack in 1995 in oklahoma city did not seem to shake america to the core. the attack in 2001 on new york city did make america feel vulnerable. it also meant tougher measures at airports and the creation of the huge department of homeland security.

some say it is bloated and overbearing. others say boston is the first city to be attacked since it was created. >> we prevent and disrupt dozens of plots and threats annually. in a lot of cases, americans are not aware of it because someone is disrupted overseas or prevented from coming into the country, or the fbi disrupt somebody early in their plotting process. >> between the capitol and the white house today, the emancipation day parade, a big public event, just like the one targeted yesterday. police say there was high- security after the events in boston, but participants were only slightly nervous. >> are you worried about being at events like this? >> i was a little bit, but my husband said we should come out and enjoy the day. >> we have some concern, but you do not want to live your life in

fear. >> it may be that america comes boston as event in just a horrible attack rather than something that makes them question the nation's identity. a a there are questions the president cannot yet answer, who did this, and why. quakes in this reflective city tonight, there will be -- >> in this reflective city tonight, there will be prayer vigils. >> we have heard from the white house that president obama will be going up to boston on thursday for what is being described as an interfaith service. do you think that kind of visit is important to the people of the city? >> i think it is very important. this is a city which really does not seem to have considered itself as possibly being

somewhere where something like this could happen. there is such a sense of profound shock that the marathon, so beloved by this city and beloved by the runners to travel all over the world to take part in it, the up what was supposed to be a celebration of athletic prowess, showcasing boston to the world, that it .urned out to be a target the president coming year will be well received, but mostly people want to know who is behind us. they are anxiously watching the investigation. >> as are the rest of us. for more on this investigation and who may have carried out these attacks, how and why, i'm joined by a former 9/11 commissioner. timothy, let me start with you. what kind of things are the

investigators looking for a the moment to give them some kind of clue, to give them the evidence they need to know who did this and why? quite certainly, the investigators are going to be looking at who, how and why. the how is critical right now. they are looking at fragments. they are looking at a nylon bag and fragments of that. they want to put together the signature of this, the fingerprint of this, in order to take it forward. they are going to look for vigilance from people. one of the things we talked about on the 9/11 commission was citizen activity and involvement. if you see something, act on it, tell people about it. that is going to be key. another thing that i think we're seeing acted out on the ground in boston is unity of effort and unity of command. how do we get a focused but

unified effort on the part of our federal people? the fbi is taking the lead on this. alcohol, tobacco and firearms are another investigative body. but also the local police, the first responders. we need to collect information from people who might have heard something. >> we do not know if this was a group, an individual, domestic or international terrorism. what have you heard from the fbi update that gives you any sense of where they are looking? >> i think there were very clear that they are leaving it wide open. they do not want to close any possibilities of the moment, which would suggest the the investigation is very wide ranging. suggest theyto think it was someone from within the u.s. who was most likely to

have done this. does not feel at the moment as if they think this is an international conspiracy. they do not see this as part of a wider plot. the suggestion is this looks more like a lone act or a small group of people. now, what motivated them, were they jihad this or anti- government extremists, that is still unclear. >> if this is not a wider plot, as janet napolitano seems to be suggesting, why are so many other places around the world stepping up security? >> we have always seen people like to copycat these things. explorel qaeda start to planes and look at experimentation on that after 9/11. a copycat bomber in london -- london has two activities coming

up right around the corner, the funeral for lady thatcher and the london marathon. i saw comments from home secretary john read this morning were on the mark, a new way of reviewing arrangements. you gather information from things happening a week ago, two days ago. >> realistically, what can we do in democratic societies to ensure the soft targets are safe? it is remarkable that there has not been an attack a and in the u.s. on a soft target since 9/11. that is extraordinary. >> on the 9/11 commission we were very aware and sensitive about overseas attacks from al qaeda or a domestic group. first, it is trying to make sure the resources are allocated

right. secondly, it is to get unity of command and unity of effort. thirdly, it is to tell the fbi that they cannot just be concerned about criminal justice and law enforcement. they have to prioritize national security. fourth, they have to be proactive in disrupting plots. fifth, we need new technology. we are seeing cameras and local communities, sensors. we will probably seek a fierce debate in the united states about commercial drones and how active those can be, and trying to make sure civil liberties and protections for our civil liberties and civil rights are set up so that we can use them or may not be able to use them. >> that, of course, is always a balance. what is the time frame you are looking at now? >> 50 forensics is under way. the search for seized -- the forensics is under way. the search for cc tv is under way. it could take a long, long time,

especially if someone has made it out of the country or has been very careful in how they have done this. it is very open-ended and very difficult to predict. >> and no one has claimed responsibility. i'm afraid i will have to leave it there. thank you for coming in. there will be more than 30 marathons around the world next weekend, and the events in boston have implications globally. insiston, organizers that the marathon will go ahead, but with a massive 36,000 runners and half a million spectators, as we were just hearing, they are taking every precaution. june kelly reports. >> the london marathon is always a day of blisters, sweat and humor. that looks incredibly heavy.

>> as big as a bag of cement, but hey, we are northerners. boston year will be in shadow. there was an immediate security review. like so many others, ms. jackson is in her final training week. this is her first london marathon. she will be setting off from doncaster with her family, and she is anxious. >> just making sure my partner is safe and ok while i am in the race. i worry about them while i am running. my son is about the same age as the boy who has been killed, so it really hits home. >> the focus will not just be on the runners this year, says one marathon veteran. >> i have every confidence in the marathon organization and the metropolitan police.

they will not let it go ahead unless they can do as much as possible, but 26 miles, you cannot guarantee. >> around 37,000 runners are taking part and more than 600,000 people are expected to be watching. the route goes through canary wharf and on past iconic buildings along the river and passed other landmarks like the houses of parliament. another massive challenge days thatcher'sret funeral. >> we will make sure we have more officers on the street looking after people, making sure they're kept safe. there is no reason to think they are less safe than they were after the terrible events in boston yesterday. >> buckingham palace is the site marathoners most want to see. here is the finish line. this year, there is a different

feel to the marathon count down. by the time people are crossing the line on sunday, the hope is the security picture will be more clear. >> as we just heard, before that marathon comes margaret thatcher's funeral tomorrow. coming up, we will have more on the fare well being planned for the prime minister. the issue of forcemeat found in products labeled as beef has caused an uproar across europe. we have results coming in from what has been a horse meat scandal right across the european union. >> our food is safer than it was a century ago, but a problem for one country can be a problem for the rest. the horse meat found in a

lasagna two months ago had traveled through four different countries. today's report includes data from 11 european union countries. france comes the worst period 47 tested positive for horse dna. greece was the second-highest. roughly one in 10. in britain, 150 tests were conducted. no positive results. today the european commission said of 20 two hundred tests it 2200cted, less than 5% -- tests it conducted, less than 5% were positive. the tests are far from conclusive and not even comparative. >> i am not satisfied. they have to be more reliable and more uniform.

the commissioner has suggested 10 tests for some states. for others, it is 100. it is evident the rules on testing are tightening. in light of today's report, no doubt there is still much to do. >> a quick look at some other news from around the world. iran has been hit by the most powerful earthquake in 40 years with tremors felt across india. there are conflicting reports about casualties, but across the border in pakistan, hundreds of homes have been destroyed. electric -- electoral authorities in venezuela have

declared nicolas maduro the winner. his challenger has urged a recount and asked venezuelans to take to the streets. today, family members and senior political figures attended a private service for the late margaret thatcher in london. it comes ahead of the funeral at st. paul's cathedral. in addition, the coffin has been moved to west westminster to allow members of parliament to pay their respects. >> the small or taj wound its way -- cordage wound its way through the streets without fuss. david cameron said she had a " lionhearted" love of britain, and it was beneath the statue of coffinnheart that her

arrived. some stopped work and came out to see the former prime minister taken underground. lady thatcher's family joined friends and relations, colleagues and members of both houses for a short private service to receive her body into the chapel. here in this gilded crypt where oliver cromwell reputedly stabled his horses and a mrs.agette once hid, thatcher will lie in state until tomorrow morning. keep vigiln will until the morning light. tomorrow, the coffin will be taken through the streets to the funeral at st. paul's cathedral, attended by former u.s. statesmen like dick cheney and

henry kissinger, but no serving u.s. statesman. >> i think it is that people feel they have to protest about it. if you do not like what she did, stay away. i hope there will not be too much trouble tomorrow. >> what there will be our 14 servicemen and women who live at the royal hospital of chelsea who will line the steps in a guard of honor. it will be here at chelsea that lady thatcher's ashes will ultimately be entered alongside those of her husband, dennis. >> remembering margaret thatcher in london and in america, remembering those killed in the attacks in boston. that brings the program to a close. thank you for watching. to tune in tomorrow. >> funding of this presentation is made possible by the freeman foundation of new york, stowe, vermont, and honolulu, newman's own foundation, giving

all profits to charity and pursuing the common good for over 30 years, fidelity investments, union bank, nowsony pictures classics, presenting "the company you keep." to eludetinues investigators. >> i don't think he is running away. i think he is trying to clear his name. >> he never be trade any of us, not once over all of these years. we made mistakes. people do what they have to do. what are the about you? what are you willing to pay for?

picking day! we're going to the enchanted garden to pick fruit. and then, we're going to help my dad build a playhouse. we have a lot to do today. i'm glad you're here. be right back! is made possible in part by... the richard king mellon foundation. dedicated for over sixty years to south western pennsylvania's quality of life, and competitive future. and by these pittsburg foundations. working together to enhance

and enrich the lives of children for more than seventy-five years. and by the arthur vining davis foundations. dedicated to strengthening america's future through education. adcasting, dedicated to strengthening america's future and contributions to your pbs station, from viewers like you. ♪ and contributions to your pbs station, ♪ a beautiful day for a neighbor ♪ ♪ would you be mine, could you be mine ♪ ♪ won't you be my neighbor? - ♪ it's daniel tiger's neighborhood ♪ ♪ a land of make-believe ♪ won't you ride along with me? ♪ - ♪ ride along - ♪ it's daniel tiger's neighborhood ♪ ♪ so much to do, so much to see ♪ ♪ won't you ride along with me? ♪ - ♪ ride along - ♪ i've got lots of friends for you to meet ♪ ♪ in this land of make-believe ♪ a friendly face on every street ♪

♪ just waiting to greet you ♪ it's a beautiful day in the neighborhood ♪ ♪ a beautiful day for a neighbor ♪ ♪ in daniel tiger's neighborhood ♪ - hi, neighbor! today is fruit picking day! i hope we get to pick strawberries. do you like strawberries? they are my favorite fruit. - hi, daniel! are you excited to pick fruit for the whole neighborhood? - yes! i can't wait! - me neither. - hi, trolley! - hello, trolley. here we go. - trolley, please take us to the enchanted garden for fruit picking day. you're going to love it. - ♪ we're going to the enchanted garden ♪ ♪ to pick some fruit won't you ride along with me? ♪ - ♪ ride along! won't you ride along with me? ♪ - here we are! - thanks, trolley! - bye, trolley!

- i can open the garden door, dad. i just have to press 3 red roses. count with me! one... two... three! whoa! amazing! hi, miss elaina. your fruit hat looks yummy! - thanks, toots! it's got my faaaavorite fruit on it! - your hat has so many fruits. which one is your favorite? - all of them! cha-cha-cha! (laughing) - i see prince wednesday! hi, prince wednesday! - a royal hello! - ahem! my family and i would like to welcome everyone to fruit picking day! (cheering) yes, yes! i declare that today we will pick... juicy red cherries! (cheering) and...

crunchy green apples! (cheering) and... - one special golden pear! (cheering) - let the fruit picking commence! - huh? - commence is a fancy word for... begin! - ok, toots, i'm going straight for the special golden pear! - daniel, daniel, daniel! let's find some red cherries! - ok! (laughing) we need to find some cherries! which tree has the cherries? look! way up in that tree! i see cherries! - let's try to pick one! - let's go! here i go! whoa! - c'mon, prince wednesday! you can reach! - almost got it! - did you get a cherry? did you get a cherry? - nope. no cherry.